Dust-collector.



No. 645,369. Patented Mar. l3, I900.

J. E. MITCHELL.

DUST COLLECTOR.

(Application filed Sept. 15, 1899.! (No Model.) 4 Sheets-Sheet l.

4 m. n p. wwl w m: nan'us PEITiS cu No. 645.369. Patented Mar. 13, I900.

J. E. MITCHELL.

DUST COLLECTOR.

(Application filed Sept. 15, 1899.)

4 Sheets-Sheet 2.

(No Model.)

No.. 645,369. Patented Mar. l3, I900. J. E. MITCHELL.

DUST COLLECTOR.

(Application filed Sept. 15, 1899. (No Model.) 4 Sheets8heet 3.

r Howls mans co. wc' cnwno" WASHINGTON. a c.

Patented Mar. l3, I900. J. E. MITCHELL. I

DUST COLLECTOR.

(Application filed. Sept. 15, 1899) 4 Sheets-Sheet 4,

(No Model.)

* men.

ATENT JOHN E. MITCHELL, OF ST. LOUIS, MISSOURI.

DUST-COLLECTOR.

SPECIFICATION forming part of Letters Patent No. 645,369, dated March 13, 1900.

Application filed September 15, 1899. Serial No. 730,615. (No model.)

To all whom zit may concern:

Be it known that I, JOHN E. MlTCHELL,'a citizen of the United States, residing at St. Louis, in the State of Missouri, have invented new and useful Improvements in Dust-Collectors, of which the following is a specification.

This invention relates to dust-collectors, and has for one of its objects to provide improved features of construction, whereby a large extent of air-filtering surface may be conveniently employed in a machine occupying comparatively small space.

It also has for its object to provide improved automatic mechanism for periodically cleaning a set or series of porous air-filtering tubes from accumulations of dust, whereby the said tubes are collapsed and suddenly stretched so as to remove the dust adhering to their inner surfaces.

My invention has for a further object to provide an improved construction and arrangement of the porous air-filtering tubes and an improved manner of mounting the same, whereby said tubes hate the same diameter throughout their length, thus permitting the cloth or other porous material to be stretched uniformly, and also allowing said tubes to present perpendicular walls when brought into position over the cut-off chamber, so that the dust can be easily dislodged from the inner surfaces of the tubes without having to slide down any portion of the cloth surface.

It is another object of my invention to provide improved means for detachably securing the porous air-filtering tubes to their places in the machine, so that a set or series of these tubes can be easily and quickly removed in case it should become necessary to repair or replace any tube or set of tubes.

Furthermore, my invention has for another object to provide improved means for making a separation in the dust collected, whereby in collecting flour-dust, for instance, the best quality or heavy white dust will be kept separate from the atmospheric black dust of low specific gravity, and whereby in collecting dust from grain-cleaning machinery the porous air-filtering tubes will be kept free l from chaff, straw, and other foreign matter that would tend to obstruct the free passage of air.

To accomplish the objects above named and for other purposes that may hereinafter appear, my invention consists in features of construction and novel combinations of devices in dust-collecting apparatus, as hereinafter described and claimed.

In the annexed drawings, illustrating the invention, Figure 1 is an end elevation of my improved dust-collector. Fig. 2 is a vertical transverse section of the same. Fig. 3 is a part side elevation 'and a part vertical longitudinal section of the machine. Fig. at is a sectional detail View on the line 4 4 of Fig. 2. Fig. 5 is an enlarged sectional View of a porous air-filtering tube.

The machine comprises a suitable supporting framework 10 for the vertically-arranged ing 12, having a dust and air inlet 13 in the upper part of one side. This casing, composed, preferably, of wooden heads 11 and sheet-iron body portion 12, may be made in two sections, upper and lower, as shown, the upper section being removable and resting on the lower section, which is in turn supported by the machine-frame. It will be observed that the casing or shell and its heads are so of a scroll around each of two large circular end openings '14, one of which is located in each head of the machine.

In the circular openings 14 and extended lengthwise of the machine there is mounted a rotary reel comprising two large circular rims 15, connected by bars or slats 16, said rims being also connected by radial arms 17 with central hubs or internal rings 18, that are mounted to rotate in bearings formed by semicircular castings 19, which are rigidly secured to the machine-frame. The reel bars or slats 16 are shouldered or rabbeted longitudinallyalong opposite edges, on the inner sides of said bars, to provide seats or recesses into which the opposite edges of longitudinally-extended boards 20 are fitted. These boards 20 are detachably secured in place by means of bolts 21 and thumb-nuts 22, said constructed or shaped as to present the form ends or heads 11 of an outer sheet-iron casbolts being secured in the reel-bars 1G and extended to the inner sides of the same for attachment of thumb-nuts 22, that may be provided with Washers or'be made sufiicien tly large to lap onto the boards 20, and thereby hold them to their seats, a bolt and nut being provided at each end of the several reelbars to be within easy access from the end of the machine.

Each of the boards is provided with a series of circular perforations of the same diameter as the porous air-filtering tubes 23 and 24, that may be made from any suitable cloth. The outer end of each cloth tube is fitted into and secured in one of these perforations of a board 20, so that each tube will open into or communicate with the interior of the machinecasing outsidethe rotary reel in which the several cloth tubes are supported and carried. The inner ends of the cloth air-filtering tubes 23 and 24 are secured to and closed by circular Wooden blocks or heads 25, a series of which are carried bya number of bars 26 and 27, extended longitudinally through the reel. Each bar 26 and 27 is supported by a number of eyebolts 28, engaging longitudinally-extended gas pipes or rods 29, that are engaged at their outer end portions in radial open-ended slots 30, formed in the reel-hubs 18, being supported in these slots by means of a stationary circular guideway 31 at each end of the machine inside the reel-hubs, each guideway 31 being secured to and held by bracket-arms 32, that are supported by the machine-frame.

It will be seen that the air-filtering surfaces in the rotary reel comprise alternating series of long cloth tubes 23 and short cloth tubes 24, and that all these tubes are closed at their inner ends, while their outer ends are open and in communication with the interior of the casing surrounding the reel. By reason of the inner ends of the several cloth tubes being closed the inner ends of the long tubes 23 can be-set very close together, and at the same time a series of shorter tubes 24 can be placed, as shown, between adjacent series of the longer tubes. This arrangement not only permits the employment of a very large extent of cloth surface in the air-filtering tubes, but is such also that the tubes can be made of the same diameter throughout their length. These tubes can therefore be cheaply manufactured, and as the cloth is cut straight with the warp the tubes will stretch uniformly and are much more easily cleaned than would be the case if they were made tapering or larger at one end than at the other. It will also be observed that the tubes in each alternate series 23 and 24 are so set in the reel that the tubes in each series will alternate with and dodge the tubes in ad joining series, thus allowing plenty of room around the inner ends of the short tubes, so that they cannot strike against the longer tubes. The bars 26, carrying the heads of the shorter tubes, are notched at their ends, so as to fit loosely around the arms 17 in the ends of the reel, which will prevent these bars and attached inner ends of the short tubes from swinging against the alternating series of long tubes. It will be apparent that any series of cloth air-filterin g tubes 23 or 24 can easily and quickly be removed through the central opening at either end of the machine by simply loosening the thumb-nuts 22 on the bolts 21 and removing the board 20, to which the outer ends of the tubes are secured, the rod 29, from which the inner ends of said tubes are supported, being easily disengaged from the slots of the reel-hubs.

The rotation of the reel is efiected intermittingly by means of pawls 33, engaging ratchets 34 on the reel-hubs. These pawls 33 are actuated from crank-arms 35.0n a crankshaft 36, mounted in the lower part of the machine-frame. Each pawl 33 may have attached thereto an arm 37, carrying a weight 38 to hold the pawl in engagement with the ratchet of one of the reel-hubs.

It will be observed that the stationary guideway 31 at each end of the machine describes a complete circle, except at the lowest point, Where it terminates with depending lips 39 at the sides of an intervening space or vertical way 40, into which the rods 29 are adapted to fall when they are brought insuccession to that point and are released by descent of knockers or hammers 41 at opposite ends of the machine. The open-ended slots 30 in the reel-hubs 18 at each end of the machine are arranged opposite the inner ends of each series of cloth tubes 23 and 24, and the rods 29, supporting the inner ends of said tubes, are adapted to fit loosely into said slots and rest against the inner surfaces of the stationary circular guideways 31, except at the opening or vertical way 40 in the lower part of each circular guideway, and at these points the ends of the rods 29 will normally rest on the hammers 41 in position to drop into the vertical ways 40 when said hammers descend. When the reel is rotated or revolved step by step, the slots 30 carry the rods 29 around,

while the stationary guideways 31 hold these rods 29, so as to keep' the cloth tubes 23 and 24 stretched to their full length, except at the lowermost rod 29, which is always free to work up and down in the spaces or ways 40 as engaged or released by the hammers 41, to knock the dust from the connected lowermost series of cloth tubes.

The nu mberof teeth in each reel-hub ratchet 34 corresponds with the series of air-filtering tubes 23 and 24, so that each revolution of the crank-shaft 36 causes the pawls 33 to bring a series of these tubes over a cut-off air-chamber 42 from which the air is shut off and which contains a conveyer 43 to carry away the dust as it is dislodged from the airfiltering tubes. While a series of the tubes 23 or 24 are at rest directly over the cut-off chamber 42, the hammers 41 at each end of the machine simultaneously strike the rod 29, supporting said series of tubes, a blow or series of blows,whereby the dust accumulated in said series of tubes is dislodged and caused to drop into the conveyer in the cutoff chamber. The hammers 41 are mounted on arms 44, that are secured to and adapted to move with sprocket-wheels 45, loosely mounted on spindles 46, that are secured to the frame 10 at opposite ends of the machine. Directly underneath the sprocket-wheels 45 and mounted in hearings on the frame 10 is a shaft 47, extended inside the machine-casing throughout the entire length of the machine. To the ends of this shaft 47 are secured sprockets 48, which are connected with the sprocketwheels 45 by chains 49, each of which is secured at one end to a lower sprocket 48, while its other end is carried over the upper sprocket 45, as shown, and has a weight 50 suspended therefrom. To one end of the shaft 47 is secured an arm 51, which is extended in a direction to be engaged periodically by rollertrips 52, that are loosely mounted on pins or spindles carried by a gear-wheel 53, mounted on the crank-shaft 36 at one end of the machine. VVhen the arm 51 is engaged by a roller-trip 52, the shaft 47 will be caused to partially turn or rotate, thereby lifting the weights 50, through the sprocket-and-chain connections at the two ends of the machine. At the same time the movements of the sprocket-wheels 45 in lifting the weights 50 will cause the hammers 41 to fall down or awayfrom the rod 29 a considerable distance. lVhen the arm 51 is released by the passing of one of the roller-trips 52, the weights 50 will instantly fall, and thereby positively force the hammer 41 to fly back with great velocity and strike the lowermost rod 29, that has meanwhile dropped into the vertical ways 40, between the dependinglips 39 of the guideways 31 at the two ends of the machine. Each time the hammers 41 are lowered the rod 29, connecting with the series of air-filtering tubes directly over the cut-0E chamber, will drop down through the vertical ways 50, thereby collapsing all the cloth tubes that connect with said rod. Now when the hammers 41 fiy back and strike this rod 29 the tubes that connect therewith are stretched so quickly and uniformly that the dust adhering to the innersurfaces of said tubes will be completely dislodged and fall down into the cut ofi chamber 42, from which it will be discharged by the conveyer 43, mounted in said chamber. While the reel is being rotated by the pawls 33, the hammers 41 remain in contact with and thereby support the rods 29 successively, which enables the rod that has just been struck or jarred to again catch the circular guideways 31, and thus prevents any liability to locking the reel.

The cut-0K chamber 42 is extended lengthwise under the lowermost portion of the reel and in direct contact therewith. On its opposite sides at the top this cut-01f chamber is provided with concavo-convex shields 54, the concaved upper sides of which are provided with a packing 55, of soft material, adapted to press against the outer surfaces of the reelslats 16, so as to effectually exclude the air from the series of cloth tubes that are directly over the cut-off chamber. For the purpose of further insuring a close air-tight joint between the cut-off chamber and the periphery of the rotary reel said cut-off chamber may be pressed upward against the reel by means of adjustably-mounted springs 56, as shown.

Between the reel-rims 15 and the heads of the machine-casing there is placeda suitable packing 57, that is secured to the casing-heads in any suitable manner and held in place against the periphery of each reel-rim 15 by means of light steel bands 58, that are extended around each rim at its circumference. Each steel band 58 is held in place by adjustable arms 59, engaging lugs 60 on the ends of the band, said arms 59 being connected with the casing-heads 11 by pivots 61 and a spring clam ping-bolt 62 being provided to draw said arms together for tightening the steel band against the packing. The object of the packing 57 and adjustable steel bands 58is to make a reliable air-tight joint between the rotating reel and its stationary casing.

In the central opening of the machine surrounded by the reel there is a dust-pan 63, that may be made of sheet metal. This pan may be supported by rods 64 on its opposite sides, resting on the bracket-arms 32 of the machine-frame. The object of this pan 63 is to provide means for catching the dust that may accumulate on the woodwork of the reel between the cloth tubes 23 and 24, it being obvious that should enough dust accumulate to give it weight it will drop 06 into this pan, whence it can be easily removed when desired.

Below the reel and the cut-0E chamber there is a settling-chamber 65, located in the bottom portion of the machine-casing. In this chamber 65 are located longitudinally-extended shafts 66 and 67, carrying sprocketwheels 68, on which are mounted chains 69, by which a number of drag bars or sweeps 70 are supported. These drag-bars 70 are arranged'to operate in such manner as to push or sweep the dust from the settling-chamber 65 and deposit it into a conveyer-box 71, whence it is discharged from the machine by means of a conveyer 72, mounted in said box.

The various moving parts of the machine may be actuated by means of power applied to a band-wheel 73 on one end of the shaft 74 of the conveyer 43 in the cut-0E chamber. The other end of this shaft 74 carries a pulley 75, connected by belting 76 to apulley 77 on one end of the shaft 78 of the conveyor 72, and the other end of this shaft 78 carries a spur-gear 79, meshing with and driving a spurgear 80 on the shaft 67, through which is actuated the sprocket mechanism, by which the drag bars or sweeps 70 are carried. This shaft 67 carries on one end a spur-gear 81, meshing with and driving the gear 53, that carries the trip-rolls 52 for controlling the weighted sprocket mechanism through which the hammers or knockers 41 are operated at proper intervals, said gear 53 being mounted on and actuating also the crank-shaft 36,with which are connected the pawls 33 for impartin g a step-by-step rotation to the reel in which the cloth tubes 23 and 24 are carried.

In operating this dust collecting and separating apparatus the dust-laden air is blown by any suitable fan (not shown) into the outside casin g of the collector at the inlet 13, and as soon as the air enters the machine it expands and partially loses control of the dust. The dust particles are traveling at great speed upon entering the machine, and by reason of centrifugal force a large percentage of the dust is caused to follow the eccentricallycurved or scroll-formed wall of the outer casing, and will thus pass rapidly around the space outside the reel and be deposited in the settling-chamber below the reel and cutoff chamber. From this chamber 65 in the bottom of the machine-casing the heavy-dust settlings will be removed by the sweeps or drag-bars and deposited in the conveyerbox '71 and conveyer 72, whereby heavy dust is discharged from the machine, as before described. A very large percentage of heavy dust is collected in this way, ordinarily something like ninety per cent. but the very light dust, including atmospheric and smoke dust of low specific gravity, is carried by the air and deposited upon the inner surfaces of the porous air-filtering tubes 23 and 24, that are mounted in the reel, the purified air passing through said tubes and discharging from each open. end of the machine. Thus in collecting flour-dust, for instance, the black dust, of comparatively-low specific gravity, is kept separate from the heavier white dust collected by the outside casing and which is of a purer quality and much brighter color. Another advantage of this apparatus is that in collecting dust from grain-cleaning machinery the straw, chaif, white-caps, and other ref use mattors are collected by the outside casing and are prevented from entering the porous airfiltering tubes. If such material should enter the cloth tubes, a large percentage of the chaff would stick to the cloth surfaces and could not easily be removed, which would result in the cloth soon becoming clogged, so as to obstruct the free passage of air.

It is not new to employ an expansion or settling chamber to settle a part of the dust before the air is filtered; but I am not aware of any dust-collecting apparatus in which the various parts are constructed, arranged, and combined for thoroughly effective and economical operation in the manner herein described, at the same time furnishinga sim ple and compact machine that is thoroughly automatic in its action and so arranged that easy access can be had to each and every part.

hat I claim as my invention is- 1. In a dust-collector, the combination of a scroll-shaped casing composed of upper and lower sections and having an air-inlet in one side of the upper section, a rotary reel mounted in said casing,alternating series of radiallyarranged long and short air-filtering tubes carried in said reel, the inner end of each of said tubes being closed and its outer end open and in communication with the interior of the surrounding casing, mechanism for rotating said reel intermittingly, knocker mechanism for jarring each series of air-filterin g tubes in succession when in its lowermost position, a cut-0E chamber in air-tight contact with the lowermost portion of the reel, a conveyer in said cut-off chamber, a settling-chamber below the cut-ofi chamber, and conveyer mech' anism in said settling-chamber, whereby the comparatively-light dust and the heavy dust are separately collected, substantially as described.

2. In a dust-collector, the combination of a scroll-shaped casing having an air-inletin one side of its upper part, a settling-chamber in the lower part of said casing, sweeps or dragbars mounted in the settling-chamber to remove deposits of dust therefrom, a conveyerbox below one side of the settling-chamber to receive the dust removed therefrom by said drag-bars, a rotary reel mounted in the scrollshaped casing above the settling-chamber, radially-arranged air-filtering tubes carried in said reel, the inner end of each of said tubes being closed and its outer end open and in communication with the interior of the surrounding casing, mechanism for rotating said reel intermittingly, knocker mechanism for jarring each series of air-filtering tubes in succession when in its lowermost position, a cut-ofi chamber in air-tight contact with the lowermost portion of the reel, and aconveyer in said cut-off chamber, whereby provision is made for separate collection of the comparatively-light dust and the heavier dust, substantially as described.

3. In a dust-collector, the combination of-a scroll-shaped casing having an air-inlet in one side of its upper part and provided at its ends with vertical heads having enlarged circular openings therein, a rotary reel mounted in said circular openings, packing secured in said openings and closely surrounding the rims of the reel, adjustable bands for clamping said packing in air-tight contact with the reel-rims, a series of radially-arranged air-filtering tubes carried in said reel, the inner end of each of said tubes being closed and its outer end open and in communication with the interior of the surrounding casing, mechanism for rotating said reel intermittingly, knocker mechanism for jarring each series of air-filtering tubes in succession, a cut-off chamber in air-tight contact with the lowermost portion of the reel, a settling-chamber below the reel and cut-ofi chamber, and conveyer mechanisms in the cut-off chamber and settling-chamber, for separate collection of the comparatively-light dust and the heavier dust, substantially as described.

at. In a dust-collector, the combination of a scroll-shaped casing composed of upper and lower sections and having an air-inlet in one side of the upper section, said casing being provided with heads having enlarged circular openings therein, a frame supporting the lower section of said casing, a rotary reel mounted in the circular openings of the casing-heads, adjustable packing secured in said openings around the rims of the reel, a series of radially-arranged air-filtering tubes carried in said reel, theinner end of each of said tubes being closed and its outer end open and in communication with the interior of the surrounding casing, mechanism for rotating said reel intermittingly, knocker mechanism for jarring each series of air-filtering tubes in succession, a cut-0E chamber having shields provided with packing in close air-tight contact with a portion of the reel periphery, a conveyer in said cut-0E chamber, a settlingchamber below the reel and cut-off chamber, and conveyer mechanism in said settlingchamber, whereby the comparatively-light dust and the heavier dust are separately collected, substantially as described.

5. In a dust-collector, the combination of a scroll-shaped casing having an air-inlet in one side of its upper part and provided at its ends with vertical heads having enlarged circular openings therein, a frame supporting said casing, a rotary reel mounted in said casing and comprising rims and hubs at each end connected by radial arms and longitudinally-extended slats carried by said rims, stationary semicircular bearings for the reelhubs, a series of radially-arranged air-filtering tubes carried by said reel, the inner end of each tube being closed and its outer end open and in communication with the interior of the surrounding casing, mechanism for rotating said reel intermittingly, knocker mechanism for jarring each series of air-filtering tubes in succession,a cut-off air-chamber having a conveyer therein, a settling-chamber located below the reel and cut-off air-chamber, drag-bars or sweeps mounted in said settling-chamber, and a conveyer to which settlings are carried by said sweeps or drag bars, all the parts of the machine being arranged for separate collection of the comparatively-light dust and the heavier dust, substantially as described.

6. In a dust-collector, the combination of a scroll-shaped casing having an air-inlet in one side of its upper part, a rotary reel mounted in said casing and provided with peripheral air-tight packing at each end, a series of radially-arranged air-filtering tubes carried by said reel, each of said tubes being closed at its inner end and having its outer end open and in communication with the interior of the surrounding casing, mechanism for rotating said reel intermittingly,];nocker mechanism for jarringeach series of air-filtering tubes in succession, a cut-off air-chamber in close air-tight contact with a lowermost portion of the reel periphery, a conveyer in said cut-off chamber, a settling-chamber located in the lower part of the casing below the reel and cut-off air-chamber, drag-bars or sweeps mounted in said settling-chamber, and a conveyer to which settlings are carried by said sweeps or drag-bars, the comparatively-light dust being collected through the cut-off chamber and the heavier dust being separately collected through the settling-chamber, substantially as described.

7 In a dust-collector, the combination with an outer casing provided with an inlet for dust-laden air, of a rotary reel mounted in said casing and comprising detachable radially-arranged long and short airfiltering tubes disposed in alternating series, all of said tubes being of the same diameter throughout their entire length and so set in the reel that the tubes in each series will alternate with and dodge the tubes in adjoining series, whereby said long and short air-filtering tubes may be placed closely together without contact with each other, each of said tubes having its inner end closed and its outer end open and in communication with the interior of the surrounding casing, mechanism for rotating said reel intermittently, a cut-off chamber in close air-tight contact with a lower portion of the reel periphery, and means for automatically collapsing and stretching each series of airfiltering tubes in succession while in perpendicular position over the cut-off chamber, the dust being thereby dislodged from the perpendicular walls of said air-filtering tubes without having to slide over an inclined surface, substantially as described.

8. In a dust-collector, the combination with an outer casing having in one side of its upper part an inlet for dust-laden air, of a rotary reel mounted in said casing and comprising long and short radially-arranged por ous air-filtering tubes that are all of the same diameter throughout their entire length, said long and short tubes being disposed in alternating series and the tubes in each series being so set in the reel as to alternate with and dodge the tubes in adjoining series to permit said tubes being placed closely together without contact with each other, each of said tubes having its inner end closed and its outer end open and in communication with the interior of the surrounding casing, mechanism for rotating the reel intermittently, a cut-off chamber in close air-tight contact with a lower portion of the reel periphery, a con veyer in said chamber, and means for automatically collapsing and stretching the perpendicular walls of each series of said long and short tubes in succession while in per pendicular position over the cut-off chamber so that the dust will be dislodged from the walls of said air-filtering tubes without having to slide over an inclined surface, sub stantially as described.

9. In adust-collector, the combination with an outer.casing, of a rotary reel mounted in said casing and provided with outer circular rims and radially-slotted hubs or internal rings connected with said rims by radial arms, said outer rims being connected with each other by longitudinally-extended slats, detachable boards seated longitudinally between said slats and each provided with a series of circular openings, a series of radiallyarranged air-filterin g tubes having outer open ends secured in said openings of the boards and communicating with the interior of the surrounding casing, heads closing the inner ends of said air-filtering tubes, longitudinally-extended bars to which said heads are secured, a series of longitudinally-extended rods engaged in the radial slots of the reelhubs, eyebolts connecting said rods and bars, stationary circular guides for said rods, mechanism for rotating the reel intermittingly, knocker mechanism to strike in succession each supporting-rod of a series of said tubes to, dislodge dust therefrom, a cut-01f chamber, and a conveyer in said chamber, substantially as described.

10. In a dust-collector,the combination With an outer casing, of a rotary reelmounted in said casing and provided with outer circular rims and radially-slotted hubs or internal rings connected with said rims by radial arms, said outer rims being connected with each other by longitudinally rabbeted or recessed slats, detachable boards seated longitudinally in the rabbeted portions of said slats and each provided with a series of circular openings, alternating series of radially-arranged long and short air-filtering tubes having open outer ends secured in the openings of said boards and communicating with the interior of the surrounding casing, heads closing the inner ends of said air-filtering tubes, longitudinally-extended bars to which said heads are secured, a series of longitudinally-arranged rods connected with said bars and engaged in the radial slots of the reelhubs, stationary circular guides for said rods, the bars that carry the heads of the short air-filtering tubes being notched to engage the radial arms in the ends of the reel, mechanism for rotating the reel intermittingly, knocker mechanism to strike in succession each supporting-rod of a series of said tubes to dislodge dust therefrom, a cut-off chamber, and a conveyor in said chamber, substantially as described.

11. In a dust-collecto1',the combination with an outer casing, of a rotary reel mounted in said casing, a series of radially-arranged airfiltering tubes carried in said reel and having inner closed ends and outer open ends in communication with the interior of the casing surrounding the reel, boards detachably mounted in the periphery of the reel and provided with series of circular openings in which the open outer ends of the air-filtering tubes are secured, thumb-nuts and bolts for detach ably securing said boards, aseries of longitudinallyarranged rods connected with the closed inner ends of the air-filtering tubes and loosely engaged with the hubs of the reel, knocker mechanism to strike in succession each of said rods, guideways for said rods, means for rotating the reel intermittingly, and a cut-off chamber, substantially as described.

12. In a dust-collector, the combination of an outer casing, a rotary reel mounted in said casing and provided with radially-slotted hubs, a series of radially-arranged air-filtering tubes carried by said'reel and having inner closed ends and outer open ends in communication with the interior of the casing surrounding the reel,,a series of longitudinallyarranged rods connected with the closedinner ends of the air-filtering tubes and loosely engaged in the radial slots of the reel-hubs, guideways for said rods, hammers or knockers to alternately engage and release each of said rods and strike forcibly against each rod in succession, supporting-arms for said hammers, weighted sprocket mechanism by which said hammer-arms are carried, an arm pro jecting from said sprocket mechanism, rollertrips to act on said arm, and a gear carrying said roller-trips, substantially as described.

13. In a dust-collector, the combination of a casin g having circular openings in its ends and an air-inlet in the upper part of one side, a rotary reel comprising outer rims mounted in said circular openings of the casing, and having internal rings connected with said rims by radial arms, packing between said reel-rims and the casing, a series of radially arranged long and short air-filtering tubes carried in the reel and each provided with a closed inner end and an open outer end in communication with the interior of the surrounding casing, said long and short series of air-filtering tubes being alternated with each other to secure compactness of structure, a dust-pan removably supported in the center of the reel, a cutoff chamber in close contact with a lower peripheral portion of the reel, packing between said chamber and reel, a conveyer in said cut-off chamber, a settlingchamber in the lower part of the outer casing, and means for removing settlings from said chamber, substantially as described.

14'. In a dustcollector, the combination of an outer casing having an air-inletin the up per part of one side, a rotary reel mounted in said casing, a series of radially-arranged straight and porous air-filtering tubes detachably mounted in said reel, mechanism for rotating the reel intermittingly, knocker mechanism for automatically collapsing and stretching each series of air-filtering tubes in successi0n,acut-0lf chamber, asettling-cham- In testimony whereof I have hereunto set her in the lower part of the casing, means for my hand in presence of two subscrlbing witremoving deposits from the cut-off chamber nesses.

and from the sett1ing-chamber, whereby the 1 JOHN E. MITCHELL. comparatively-light dust and the heavier dust Witnesses: are separately collected, and a dust-pan in the AUGUSTINE GALLAGHER,

center of the reel, substantially as described. I P. H. LITGHFIELD. 

